Since this traffic event thing has the feature of being able to warn drivers in the area, is it acceptable to use it for events which may have traffic impacts, but do not have closures, and are large enough in scale that you can't put any closures which make sense into Waze anyway?

I'm thinking (too late for this year) specifically of large running/walking events (biking events would quality too) like the Hood to Coast Relay. It is 198 miles long, 12,600 runners and 3,600 volunteers, using about 3,000 support vehicles. It runs primarily along US-26 from Mt. Hood into Portland, and then on US-30 from Portland to the coast, and a little bit of US-101 on the coast.

Oregon DOT puts out a warning to drivers each year. But again, there's no closures. Just awareness that there are some lane closures and possibly some other traffic impacts in congested areas.

Is this kind of thing valid for a Mega Event just from a "warning" standpoint?

I had send a request for road closure to Event Center requesting for road clossing for our Malaysia Mega Event that is our Malaysia Day Parade on 12 September2013. Since this is our National and Historic event of the country, a vey massive jammed will happened. And most all the route to the event centre will be closed for public from 0500 till 1300 hrs(+8hrs GMT) on 16September2013. ( to be exact the event is going to happen in 9 hrs time and road closure will begin in 7 hrs time. So far I dont get any respond to my request.

I can see it in the responses, BUT it hasn't been coded. The problem may have been you submitted the request too late for Waze to do anything about it. These closures have to be inputted into the system manaually - the earlier you submit them, the more time Waze has to implement them. Remember, Waze HQ is in Israel and is closed on Friday & Saturday for their weekend.

The problem there is no set deadline. If depending on how big the event is waze will put more effort into getting it set up. So some events get picked up and other do not. We do need to work out better communications so we know what's going on when we submit an event.

I'd second this use. We have a very large number of events in London (UK) that affect routing but are either too short to make edits and/or too complex. For example, the Notting Hill Carnival this long weekend. Transport for London issues regular advice that could be incorporated (subject to copyright/legal issues).

This is actually something for March through April 2014 but it seems there will be a One Fund Relay that will go through 14 states, starting in Santa Monica, CA and ending in Boston, MA. Don't know whether this will affect traffic or not or what the route is but it is reported that it will follow the Boston Marathon route (which includes busy roads [Route 9, Boylston St, Storrow Drive]). I will try to see if I can get more details but for now, here is the news report:

~Edit~So I found the official website that shows the proposed route going through California, Arizona, New Mexico, Texas, Oklahoma, Missouri, Illinois, Indiana, Ohio, Pennsylvania, New Jersey, New York, Connecticut, and Massachusetts. The route is actually divided up into segments (stages) of about 10 miles and the website states what time each segment will start.